The present invention relates to a detergent composition such as detergent for shampoo, detergent for body wash, detergent for face wash, detergent for hand wash, and detergent for dish wash.
Heretofore, detergents for shampoo, detergents for body wash, and the like, which were to be washed away after being applied to skin or hair, were mostly composed of detergent bases such as salts of alkyl sulfate, salts of polyoxyalkylene alkyl ether sulfate, etc. However, since the use of such detergent bases alone leads to poor foaming, an amide such as a monoethanolamide or a diethanolamide is also used in order to enhance the foaming property of the detergent.
However, a monoethanolamide is a solid at normal temperature and therefore it presents a handling problem at the time of manufacture. In addition, it presents another problem such as deposition of crystals when stored at a low temperature. On the other hand, a diethanolamide is associated with concern over the possibility of the formation of nitrosamine.
Generally, it is known that the optimum pH values of foaming agents vary depending on the combinations with surfactants.
There is a description that lauroyl N-methylmonoethanolamide is effective as a foam booster for a salt of alkyl sulfate in JAOCS 48(11), 674-677(1971). However, no description is made of skin irritation, pH, and storage stability.
U.S. Pat. No. 4,070,309 describes a composition which has a pH value of 7 to 10 and comprises an anionic surfactant, a nonionic foam booster, and an alkylphenol derivative, wherein myristoyl N-methylmonoethanolamide is an example of the nonionic foam booster. However, this technique cannot improve both of foamability and storage stability at the same time.
Japanese Patent Application Laid-Open (JP-A) No.10-330783 discloses in examples thereof a combination of an amide sulfate ester-based surfactant and coconut oil fatty acid N-methylethanolamide. However, this technique merely discloses effects based on the detergency and foamability of the amide sulfate ester-based surfactant as the main detergent base and the addition of a small amount of coconut oil acid N-methylethanolamide. Accordingly, no mention whatsoever is made of obtaining a detergent composition which causes little skin irritation and ample foaming.
The object of the present invention is to make it possible to produce, with ease in handling, a detergent composition which has low skin irritation, good foamability and excellent stability when stored as a product.
The present inventors found that an amide alcohol having a specific structure exhibits an excellent foamability in a weakly acidic range, which is said to has low skin irritation, and improves stability when stored as a product.
The present invention relates to a detergent composition comprising 0.8 to 20 weight % of (A) an amide alcohol represented by the following general formula (1) [hereinafter referred to as component (A)] and (B) at least one surfactant selected from an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant [hereinafter referred to as component (B)], wherein the pH at 25xc2x0 C. of the 20-fold diluted aqueous solution of the detergent composition is 4.5 to 6.8. 
In the formula (I), R1COxe2x80x94 is a saturated or unsaturated acyl group which has 6 to 24 carbon atoms and may have a hydroxy group; R2 is a linear or branched alkyl group having 1 to 3 carbon atoms; and R3 is a linear or branched alkylene group having 1 to 6 carbon atoms or alkenylene group having 2 to 6 carbon atoms.
The detergent composition of the present invention can be produced with ease in handling. The detergent composition has good foamability at the time of washing, excellent stability when stored as a product and low skin irritation. Therefore, the detergent composition is most suitable for such uses as detergent for shampoo, detergent for body wash, detergent for face wash, detergent for hand wash, etc.
The composition of the present invention may further contain at least one selected from (C) an antimicrobial agent, (D) a conditioning component, (E) a pearling agent, and (F) a plant extract.
If the composition contains (C) an antimicrobial agent, the composition exhibits a high antimicrobial effect. If the composition contains (D) a conditioning component, the composition provides a comfortable feeling after use and a sufficient conditioning effect to the skin or hair. If the composition contains (E) a pearling agent, the composition provides a good appearance. If the composition contains (F) a plant extract, the composition provides effects, such as a moisturizing effect, an anti-inflammatory effect, and the like, which are characteristic of the extract, while maintaining good stability of the composition.
In the general formula (1) for the component (A), R1COxe2x80x94 is preferably a saturated or unsaturated acyl group having 8 to 18 carbon atoms. Preferably, the R1COxe2x80x94 groups are acyl groups derived, for example, from octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, docosanoic acid, linoleic acid, isostearic acid, oleic acid, coconut oil fatty acid, palm oil fatty acid, palm kernel oil fatty acid, etc. Particularly preferably, the R1COxe2x80x94 groups are acyl groups derived from decanoic acid, dodecanoic acid, coconut oil fatty acid, palm oil fatty acid, and palm kernel oil fatty acid, etc. R2 is preferably a methyl group and R3 is preferably an ethylene group.
From the viewpoint of the foamability of the detergent base and the stability when stored as a product, the component (A) is incorporated in a proportion of 0.8 to 20 weight %, preferably 1 to 10 weight %, and more preferably 1 to 5 weight % into the detergent composition of the present invention.
The anionic surfactant, nonionic surfactant, and amphoteric surfactant as the component (B) are selected from those generally used for cosmetics and toiletries, etc.
Examples of the anionic surfactant include salts of alkyl sulfate, salts of polyoxyalkylene alkyl ether sulfate, salts of polyoxyalkylene alkyl ether acetic acid, salts of polyoxyalkylene alkyl ether phosphate, salts of alkyl phosphate, salts of N-acylmethyltaurine, salts of acylglutamic acid, salts of acyloyl-xcex2-alanine, salts of alkylsulfosuccinic acid, salts of polyoxyalkylene alkylsulfosuccinic acid, fatty acid salts, etc. In particular, salts of alkyl sulfate, salts of polyoxyalkylene alkyl ether sulfate, salts of polyoxyalkylene alkyl ether acetic acid, salts of polyoxyalkylene alkyl ether phosphate, and salts of alkyl phosphate are preferable. Further, salts of alkyl sulfate and salts of polyoxyalkylene alkyl ether sulfate are preferable from the viewpoint of higher foamability. These anionic surfactants may be used singly or in a combination of two or more. Particularly preferred an ionic surfactants are those represented by the following general formula (2).
R4xe2x80x94Oxe2x80x94(CH2CH2O)nxe2x80x94SO3M
wherein R4 represents a saturated or unsaturated hydrocarbon group having 10 to 18 carbon atoms; n represent a number in the range of 0 to 5; and M represents an alkali metal, an alkaline earth metal, ammonium, an alkanolamine, or a basic amino acid.
In the general formula (2), n is the average of the numbers of moles of ethylene oxide added (hereinafter indicated as EOp) and is preferably 0 to 3 from the viewpoint of foamability. More preferably, n is 1 to 3 because of lower skin irritation. Further, it is preferable that the proportion of the anionic surfactant represented by the general formula (2) is 60 to 100 weight % of the total anionic surfactants.
Examples of the nonionic surfactant include alkyl polyglycosides, polyoxyalkylene (preferably ethylene) alkyl or alkenyl ether, polyoxyalkylenesorbitan fatty acid esters, sorbitan fatty acid esters, polyoxyalkylenesorbitol fatty acid esters, polyoxyalkyleneglycerin fatty acid esters, polyglycerin fatty acid esters, fatty acid monoglycerides, polyethyleneglycol fatty acid esters, fatty acid alkanolamides other than the component (A), etc.
Examples of the amphoteric surfactant include betaine alkylaminoacetates, alkylamine oxides, alkylamide propylbetaine, alkylhydroxysulfobetaines, amidoamino acids (imidazoline-based betaines), etc.
As to the component (B), one or more of the surfactants selected from the anionic surfactant, the nonionic surfactant, and the amphoteric surfactant may be used in combination. From the viewpoint of detergency, the total of the surfactants constituting the component (B) is preferably 5 to 50 weight %, more preferably 10 to 30 weight %, of the detergent composition of the present invention. It is preferable that the component (B) includes an anionic surfactant. In particular, it is preferable that the component (B) includes an anionic surfactant represented by the general formula (2), i.e., a salt of a specific alkyl sulfate or polyoxyalkylene alkyl ether sulfate, from the viewpoint of foamability.
Examples of the antimicrobial agents as the component (C) include triclosan, triclocarban, piroctone olamine, zinc pyrithione, selenium disulfide, 3-methyl-4-(1-methylethyl)phenol, etc. as well as the antimicrobial agents described in xe2x80x9cScience of Antiseptics Bactericides for Cosmetics and Medicinesxe2x80x9d edited by John J Cabara, Fregrance Journals, 1990. Among these antimicrobial agents, triclosan, triclocarban, piroctone olamine, and zinc pyrithione are particularly preferable.
Besides, a cationic surfactant may be used as the component (C). More specifically, the examples include quaternay ammonium salts represented by the following general formula (C1), benzalkonium salts and benzethonium salts represented by the general formula (C2), chlorhexidine salts represented by the general formula (C3), and pyridinium salts represented by the general formula (C4). 
wherein R5 and R6 are the same or different and each represents an alkyl group, an alkenyl group, or a hydroxyalkyl group each having 6 to 14 carbon atoms such that the sum of the carbon atoms is 16 to 26; R7 and R8 are the same or different and each represents an alkyl group or a hydroxyalkyl group each having 1 to 3 carbon atoms or a polyoxyethylene group in which the average of the numbers of moles of ethylene oxide added is not more than 10; and Z represents a halogen atom, an anionic residue of an amino acid, a fatty acid, or a phosphoric, phosphonic, sulfonic or sulfuric ester having a straight-chain or branched alkyl or alkenyl group made up of 1 to 30 carbon atoms, or an anionic oligomer or polymer containing a formalin-condensation product of a polycyclic aromatic compound which may have a styrenesulfonic acid whose degree of polymerization is not less than 3 or a hydrocarbon group as a substituent. 
wherein R9 represents a hydrocarbon group having 8 to 14 carbon atoms or the group represented by 
; and Z has the same meaning as above. 
wherein Zxe2x80x2 represents gluconic acid, acetic acid, or hydrochloric acid. 
wherein R10 represents a straight-chain or branched alkyl group having 6 to 18 carbon atoms and Z has the same meaning as above.
In the general formula (Cl), R5 and R6 are preferably an alkyl group having 8 to 12 carbon atoms; and R7 and R8 are preferably an alkyl group having 1 to 3 carbon. In the general formula (C2), R9 is preferably an alkyl group having 8 to 14 carbon atoms. In the general formula (C4), R10 is preferably an alkyl group having 8 to 16 carbon atoms. In the general formulae (C1), (C2), and (C4), Z is particularly preferably a halogen atom.
Specific examples of the cationic surfactants that are suitable include benzalkonium chloride, benzethonium chloride, cetylpyridinium chloride, chlorhexidine gluconate, chlorhexidine acetate, chlorhexidine hydrochloride, etc. In particular, the cationic surfactants represented by the general formula (C2), e.g., benzalkonium chloride and benzethonium chloride, are preferable.
A higher effect of the component (C) can be obtained if a combination of a cationic surfactant and an antimicrobial agent other than the cationic surfactant is used.
From the viewpoint of obtaining a sufficient antimicrobial effect, the content of the component (C) in the detergent composition of the present invention is preferably 0.005 to 5 weight %, particularly preferably 0.1 to 4 weight %, and further preferably 0.4 to 3 weight %.
The conditioning component as the component (D) is a component that imparts to the hair and body such properties as smoothness, softness, and moisturizing effect. Specific examples of the conditioning component include oils, silicones, cationic surfactants, and cationic polymers. These may be used singly or in a combination of two or more.
The term xe2x80x9coilsxe2x80x9d as used herein means solids or liquids which are dispersible in water and ordinarily used in cosmetics and the like and which exclude silicones. Examples of the oils include hydrocarbons such as vaseline; higher fatty acid monoesters such as isopropyl palmitate; higher alcohols such as cetyl alcohol; and plant oils and animal oils such as camellia oil, macadamia nuts oil, mink oil, olive oil, safflower oil, soybean oil, jojoba oil, and lanolin.
One or more kinds of the oils may be used. The content of the oil in the composition is preferably 0.1 to 10 weight %, more preferably 0.2 to 7 weight %, and particularly preferably 0.2 to 5 weight %.
Examples of the silicones include those indicated below.
(1) Dimethylpolysiloxanes represented by the following formula
(Me)3Si[(Me)2SiO]dxe2x80x94Si(Me)3
wherein Me represents a methyl group and d is a number of 3 to 20000.
(2) Amino-modified silicones
Although various kinds of amino-modified silicones may be used, particularly preferred are those having average molecular weights of about 3000 to 100000 and described under the name of amodimethicone in the CTFA dictionary (U.S.A., Cosmetic Ingredient Dictionary), the third edition. It is preferable that the above-mentioned amino-modified silicones are used as aqueous emulsions. Commercialized products of these amino-modified silicones include SM 8702C (manufactured by Toray Dow Corning Silicone Co. Ltd.) and DC 929 (manufactured by Toray Dow Corning Silicone Co. Ltd.).
(3) Other examples include polyether-modified silicones, methylphenol polysiloxanes, fatty acid-modified silicones, alcohol-modified silicones, alkoxy-modified silicones such as epoxy-modified silicones, fluorine-modified silicones, cyclic silicones, alkyl-modified silicones, etc.
One or more kinds of the silicones may be used. The content of the silicone in the composition is preferably 0.1 to 10 weight %, more preferably 0.2 to 5 weight %, and particularly preferably 0.2 to 3 weight %.
Examples of the cationic surfactant include quaternary ammonium salts represented by the following general formula (3). 
wherein at least one of R11, R12, R13, and R14 represents an alkyl or alkenyl group which has 16 to 28 carbon atoms and may be substituted with an alkoxy group, alkenyloxy group, alkanoylamino group, or alkenoylamino group each having 16 to 28 carbon atoms so that the rest each represents a benzyl group, an alkyl or hydroxy alkyl group having 1 to 5 carbon atoms, or a polyoxyethylene or polyoxypropylene group in which the sum of the numbers of moles added is not more than 20; and Zxe2x80x3xe2x88x92 represents a halogen ion or an organic anion.
In the general formula (3), it is preferable that one or two of R11, R12, R13, and R14 are each a straight-chain or branched alkyl group having 16 to 22 carbon atoms and the rest is a methyl group. Further, it is preferable that Zxe2x80x3xe2x88x92 is a chlorine ion.
Preferred examples of the cationic surfactant include N-stearyl-N,N,N-trimethylammonium chloride, N,N-distearyl-N,N-dimethylammonium chloride, N,N-dibehenyl-N,N-dimethylammonium chloride, etc.
One or more kinds of the cationic surfactants may be used. The content in the composition is preferably 0.01 to 10 weight %, more preferably 0.05 to 10 weight %, and particularly preferably 0.05 to 7 weight %.
Examples of the cationic polymer include cationized cellulose derivatives, cationic starch, cationized guar gum derivatives (e.g., Jaguar C-13xe2x80x2S, Jaguar C-17, and Jaguar C-16 manufactured by Celanese Corporation), homopolymers of diallyl quaternary ammonium salts, diallyl quaternary ammonium salt/acrylamide copolymers, diallyl quaternary ammonium salt/acrylic acid copolymers, diallyl quaternary ammonium salt/acrylic acid/acrylamide ternary copolymers, quaternized polyvinylpyrrolidone derivatives, quaternized vinylpyrrolidone vinylimidazole polymers(e.g., LUVIQUAT manufactured by BASF Corp., etc.), polyglycol/polyamine condensation products, vinylimidazolium trichloride-vinylpyrrolidone copolymers, hydroxyethyl cellulose/dimethyldiallyl chloride copolymers, vinylpyrrolidone/quaternized dimethylamino methacrylate copolymers, polyvinylpyrrolidone/alkylamino acrylate/vinylcaprolactam copolymers, vinylpyrrolidone/methacrylamidopropyl trimethylammonium chloride copolymers, alkyl acrylamide/acrylate/alkylaminoalkyl acrylamide/polyethylene glycol methacrylate copolymers, adipic acid/dimethylaminohydroxypropylethylenetriamine copolymers (e.g., CALTALETINE manufactured by U.S. Sandos Corp., etc.), and cationic polymers described in JP-A NO. 53-139734 and JP-A NO. 60-36407. In particular, cationized cellulose derivatives are preferable.
One or more kinds of the cationic polymers may be used. The content in the composition is preferably 0.01 to 5 weight %, more preferably 0.01 to 3 weight %, and particularly preferably 0.03 to 2 weight %.
One or more kinds of the component (D) may be used. The content in the composition is 0.01 to 20 weight %, preferably 0.1 to 10 weight %, and more preferably 0.1 to 7 weight %.
The pearling agent as the component (E) is a component that can impart a pearl luster to the appearance of the composition. In the present invention, compounds, known as emulsifying agents or pearling agents, such as esters made up of glycols and fatty acids (e.g., monoesters and diesters) and long-chain dialkyl ethers can be used as the pearling agent. Specific examples of the pearling agent include organic compounds such as ethylene glycol distearate, ethylene glycol monostearate, diethylene glycol distearate, ethylene glycol dipalmitate, distearyl ethers, etc. From the viewpoint of costs and availability, esters made up of glycols and fatty acids are suitable. In particular, ethylene glycol monostearate and ethylene glycol distearate are suitable. More particularly, ethylene glycol distearate is preferable.
The content of the component (E) in the composition is preferably not less than 0.3 weight % and less than 10 weight %, more preferably 1.0 to 5.0 weight %, and most preferably 1.0 to 4.0 weight % from the viewpoint of appearance.
The appearance of the detergent composition of the present invention has a pearl luster. This composition can be prepared, for example, by the steps of melting a mixture of the component (A), the component (B), the component (E), and water with stirring by heating up to a temperature not less than the melting point of the component (E) so as to produce a homogeneous state, adding optional components to the homogeneous mixture, and cooling the mixture while being stirred so that the crystals of the component (E) are deposited. Alternatively, it is possible to prepare the composition by the steps of melting a mixture of the component (B), the component (C), and water with stirring by heating up to a temperature not less than the melting point of the component (E), adding the component (E) and dissolving homogeneously the component (E), adding optional components, and cooling the mixture while being stirred so that the crystals of the component (E) are deposited.
Further, it is possible to prepare the detergent composition by the steps of preparing a concentrated pearling composition in advance and incorporating the concentrated composition into the detergent composition at the time of manufacture thereof at a temperature not more than the melting point of the component (E).
The concentrated pearling composition is a composition having an appearance of pearl luster. Examples of the composition include EUPERLAN series of COGNIS Corp. A preferred example is the following composition.
A composition containing:
the pearling agent as the component (E) in an amount of 10 to 50 weight %, preferably 15 to 30 weight %;
the component (B) in an amount of 10 to 50 weight %, preferably 10 to 35 weight %; and
the component (A) in an amount of 0.1 to 20 weight %, preferably 0.5 to 15 weight %.
The detergent composition of the present invention, which is obtained in the above-described way, exhibits good dispersion stability of the component (E) in the product. Therefore, the detergent composition of the present invention is most suitable as a detergent composition having a pearl luster and examples of the composition include detergents for shampoo, detergents for body wash, detergents for face wash, detergents for hand wash, etc.
Examples of theplant extract as the component (F) include the plant-based extracted essences commercialized by ICHIMARU FALCOS Co., Ltd. Specific examples thereof include aloe, aloe vera, ginkgo, fennel, seaweeds, root of kudzu, chamomile, kiwi, cucumber, luffa, gardenia, rice bran, peach, yuzu, adlay, etc.
The content of the plant extract as the component (F) in the composition is preferably 0.001 to 10 weight %, more preferably 0.005 to 5.0 weight %, and most preferably 0.01 to 3 weight % from the viewpoint of stability and moisturizing effect.
The pH (25xc2x0 C.) of the 20-fold diluted aqueous solution of the detergent composition of the present invention is 4.5 to 6.8, preferably 5.5 to 6.8, because these pH values fall in the closeness of the pH of healthy human skin.
The detergent composition of the present invention can be prepared with ease in handling at the time of manufacture and the detergent composition has a good foamability when used, has excellent stability when stored as a product, and has a low skin irritation. Therefore, the detergent composition is most suitable as a detergent for shampoo, a detergent for body wash, a detergent for face wash, a detergent for hand wash, etc.
Further, the composition provides a high antimicrobial effect if the composition is incorporated with an antimicrobial agent; the composition provides a good feeling after use or a sufficient conditioning effect to the skin or hair if the composition is incorporated with a conditioning component; and the composition provides a good appearance if the composition is incorporated with a pearling agent.
The detergent composition of the present invention may appropriately contain water-soluble polymers such as methyl cellulose, hydroxyethyl cellulose, carboxyvinyl polymers, and poly saccharides (xanthan gums); solubilizers such as glycerin, sorbitol, and ethanol; chelating agents such as ethylenediaminetetraacetic acid (EDTA), and phosphonates; antiseptics such as parabens and benzoic acid; anti-inflammatory agents such as dipotassium glycyrrhizinate and allantoin; antioxidants such as dibutylhydroxytoluene; ultraviolet absorbers; pH adjusting agents such as malic acid, citric acid, potassium hydroxide, and sodium hydroxide; dyes; perfumes; etc.
Further, the detergent composition of the present invention may take any of such forms as solid, liquid, paste, etc.